1. Technical Field
The present invention pertains to improvements in methods and apparatus for producing and collecting sterile surgical slush. In particular, the invention is an improvement of the methods and apparatus disclosed in our U.S. Pat. No. 5,331,820 and the patents cited therein. The disclosures in those patents are expressly incorporated herein in their entireties.
2. Discussion of the Prior Art
Our aforesaid U.S. Pat. No. 5,331,820 addresses the problem of removing congealed frozen sterile medium from the sides of a sterile drape container in a surgical slush machine. Specifically, the sterile drape container is conformed to a cooled basin to establish a sterile field above the basin. The drape container collects a frozen sterile medium (e.g., saline) in a sterile slush-like consistency. The frozen medium tends to attach to the sides of the drape container in large clumps or pieces rather than automatically collecting within the container interior. Prior to the invention in U.S. Pat. No. 5,331,820, operating room personnel attempted to detach frozen pieces from the drape container sides by scraping or impacting the pieces. This is highly undesirable since impacting and scraping can easily tear the drape and compromise the required sterile field. The U.S. Pat. No. 5,331,820 discloses a technique for automatically manipulating the drape relative to the basin wall to thereby cause the frozen congealed medium to detach from the drape sides and collect interiorly as the desired slush. Some of the embodiments disclosed in the patent cyclically move a plate or disk disposed between the drape and basin to manipulate the drape. The disk is described as being either secured to a movable machine or secured directly to the drape. It has been found that, for many applications, it is more convenient to have the plate or disk secured directly to the drape. Such an arrangement insures proper positioning of the drape in the cooling basin to effect automatic drape manipulation.
The present invention is concerned with optimizing the embodiment suggested in the aforesaid patent wherein the disk or plate is secured directly to the drape.